Checking timing on a Peugeot 308 with dual VVT and VANOS

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Checking timing on a Peugeot 308 with dual VVT and VANOS

Postby Tivtech » Mon Feb 27, 2017 6:29 am

Hello All,

We have this Peugeot 308 (1600cc, dual VVT + VANOS, engine code 5FW) where timing belt has been changed due to excessive wear and now, when cold, engine idles roughly and then stalls. Revving the engine a bit keeps it alive until pedal released and then it stalls. The following tests have been done to try and diagnose the problem:

1. Timing has been triple checked as per Autodata diagrams and done with proper camshaft locking devices. There seems to be some discrepancy between the Autodata drawing and the VVT hubs actual positions, though it might be insignificant. I'm attaching a relevant picture, Inlet camshaft hub on the left,
2. Both CMP sensors seem to be outputting a good signal, tested with a LED light, not a scope. It seems that PICO guided tests also talk just about proper waveforms of the sensor signals and not their relative timings.
3. The CKP sensor signal has not been tested due to more difficult access but the engine runs hence it should be present, though maybe the signal might be marginal and thus affecting sensor signals coherence as described below.
4. The VANOS motor (responsible for changing inlet valve lift range) seems to behave as it should when actuated with a diagnostics scanner (checked with valve cover removed for visibility).
5. No PCM faults are reported.
7. When the exhaust VVT solenoid is disconnected engine starts and runs smoothly and doesn't stall.
8. PCM datastream points to a possible problem with CMT and CKP coherence ("status of coherence between the positions of the camshaft and the crankshaft ==> not coherent", see attached picture).
9. When engine is running smoothly after being started with exhaust CMP sensor disconnected, disconnecting also the inlet CMP sensor as well as the VANOS motor connector doesn't stall the engine.

Thus what we want to compare timings with a scope of the inlet CMP, exhaust CMP and the CKP sensor signals to a reference timing diagram from a known good running engine.
Problem is,
1. We don't have such a reference timing diagram.
2. Even if we had one, it seems that the VVT + VANOS systems will make timing comparisons difficult if not impossible due to the variable timing which is not fixed or predictable, unless we disable them by disconnecting the VVT solenoids as well as the VANOS motor to keep timing static. Still this doesn't seem enough because the camshaft VVT hubs (or whatever they're called) that change camshaft timing based on VVT solenoid control of oil pressure to them seem to be freewheeling within their allowable range so without control might cause unpredictable results.

In short, we're a bit lost in this mess... :D and need some help from someone experienced with this motor and how to check it's timing. What we need:
1. A timing diagram from a known good running motor for comparison, as well as an answer whether disconnecting the VVT solenoids and VANOS motor brings the engine to a known static timing.
2. A method that works to check timing with a scope during cranking or engine running.
3. Any other good ideas...
Thanks for any helped offered.
Attachments
20170213_195355.jpg
20170213_195623.jpg
20170215_194159.jpg
20170216_144305.jpg
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Re: Checking timing on a Peugeot 308 with dual VVT and VANOS

Postby STC » Mon Feb 27, 2017 11:32 pm

Hi TivTech
Impressive First Post :) :)
8. PCM datastream points to a possible problem with CMT and CKP coherence ("status of coherence between the positions of the camshaft and the crankshaft ==> not coherent", see attached picture).


I would be logging into "ServiceBox" for the factory timing instructions.

3. The CKP sensor signal has not been tested due to more difficult access

"No Pain No Gain" :)

Scope both CMP's and CKP back probed at ECU Connector - Not good practice to measure sensor outputs at the sensor.

2. A method that works to check timing with a scope during cranking or engine running.

Paralyse Spark or Fuel to get a trace cranking.

reference timing diagram from a known good running engine.
Problem is,
1. We don't have such a reference timing diagram.


Pico have a "Waveform Library" If you have an Automotive Pico then you will have open access to it. If not then there is some chance that someone on the forum maybe able to help you.

I would advise you to upload your CMP (Exh & Inl) CKP capture from Ignition On > Cranking > Idle > Fast Idle 2500 rpm.

Use a timebase of 50 / 100 mS/div
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Re: Checking timing on a Peugeot 308 with dual VVT and VANOS

Postby arjen » Sat Mar 04, 2017 9:36 am

Could be the camshaft sensor connectors have been switched.
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Re: Checking timing on a Peugeot 308 with dual VVT and VANOS

Postby tode » Mon Mar 06, 2017 10:04 pm

Do not worry friend from the picture that you insert here, it seems that you have failed to mount VANOS, reversing the intake and exhaust. The problem that you have is just a clear symptom
They look the same but they are different you follow the written and former.
Attachments
errate Vanos.jpg
tode
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Re: Checking timing on a Peugeot 308 with dual VVT and VANOS

Postby PicoKev » Mon Mar 06, 2017 11:30 pm

tode,

Brilliant spot!
I congratulate you on your eyesight and detective skills.... Both vastly superior to mine. :oops:
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